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Case Study
Client: Car retail operation and filling station owner
Site: Operational Filling Station in the Northwest.
Contamination: Heavy soil and groundwater contamination from historic use of the site as a PFS. The site was investigated by an environmental consultant prior to MES involvement in the remediation. The investigation highlighted heavy impact to the front of the site in the vicinity of the forecourt and former forecourt areas. The impact was indicated to be waterborne. Groundwater concentrations of benzene were found at concentrations ranging between 19 – 16,932µg/l. other volatile hydrocarbons also recorded significant concentrations. The site was to be sold, as a condition of the deal the site was to be made fit for continued commercial use prior to sale of the PFS and car dealership.
Remediation Strategy: The key objective of the strategy was to improve groundwater quality and render the site fit for continued commercial use. It was considered that based on the findings of the environmental assessment that a groundwater treatment/containment trench should be installed. This multi-phased system comprised groundwater management, using pump and treat technology to prevent migration offsite, with air sparge and vacuum extraction which was installed across the length of the trench. The trench consisted separate treatment zones which could be targeted to a greater or lesser extent during the programme dependant on field results. Upon commissioning vapour samples typically recorded >2000ppm volatile petroleum hydrocarbons.
Project Programme:
Results and Conclusions:
Vapour phase contamination reduced from >2000ppm to <100ppm within four months.
Significant reduction in volatile petroleum hydrocarbons achieved within groundwater at the site.
The system used enabled rapid site remediation to allow the owner to press ahead with the sale of the property.
